The Dragon is an 8-bit personal computer based upon the Motorola MC6809E microprocessor. Made in Wales by Dragon Data Ltd., two variants were sold in the UK: the Dragon 32 (basic version, 32K RAM) and the Dragon 64 (64K RAM, serial port, other very minor differences). The on-board ROM contains a version of Microsoft Extended Colour BASIC, but more advanced operating systems like OS-9 and FLEX are available.
An NTSC version of the Dragon 64 was released in the USA as the Tano Dragon, and Eurohard repackaged it in Spain as the Dragon 200.
David Linsley has written a comprehensive history, available here.